Sir Alex Ferguson welcomed Dimitar Berbatov's third hat-trick of the season in Manchester United's 5-0 win over Birmingham and now hopes Wayne Rooney can enjoy a touch of luck in front of goal.

The Bulgarian opened his account in the second minute, added another before half-time and then tapped home a Ryan Giggs cross to become the first United player to score three hat-tricks in a season since Ruud van Nistelrooy.

The treble took Berbatov's goals tally for the season to 18, all but one of which have come in the Premier League. That number is 15 more than Rooney, who is performing manfully, yet rarely looks like finding the target, however, Ferguson said: "We hope the goals are going to come for Wayne. He is working his socks off."

Ferguson continued: "He produced some great football and his control from Edwin van der Sar's kick for the fourth goal was fantastic."

It was Berbatov who took the plaudits from a victory that consolidated United's status as league leaders and extended their unbeaten run this season to 22 matches ahead of Tuesday's trip to Blackpool.

"It was a marvellous performance from Dimitar," said Ferguson. "He could have scored more. We were a bit wasteful with our finishing at times but you can't complain at the performance."

Veteran Ryan Giggs drilled home just before the interval to confirm his well-being after agreeing to stay at Old Trafford for a further season.

And, after a series of failed attempts, Nani wrapped up the scoring midway through the second period.

"It certainly helps the goal difference, there is no question about that," said Ferguson. "We have some tough games ahead but hopefully the players can grasp the nettle.

"We have some experience. We have the squad. Hopefully we can manage all the games we have ahead."